Ответ:

  1. \(\sqrt{27}=\sqrt{9\cdot3}=3\sqrt3\).
  2. \(\sqrt{50}=\sqrt{25\cdot2}=5\sqrt2\).
  3. \(\sqrt{245}=\sqrt{49\cdot5}=7\sqrt5\).
  4. \(-\frac12\sqrt{80}=-\frac12\cdot4\sqrt5=-2\sqrt5\).
  5. \(0.2\sqrt{300}=0.2\cdot10\sqrt3=2\sqrt3\).
  6. \(\sqrt{675}=\sqrt{225\cdot3}=15\sqrt3\).